Numerous studies were published over the last 50 years to investigate whether diet is associated with the etiology of acne. Although older studies well known by dermatologists that refute the association between acne and diet exist, their scientific foundation is weak. New articles have recently brought to light evidence contrary to previous findings. Therefore, we would like to investigate whether diet, directly or indirectly, influences one or more of the four fundamental etiopathogenic pillars of acne: (1) hyperproliferation of basal keratinocytes, (2) increase of sebaceous production, (3) colonization by Propionibacterium acnes, and (4) inflammation.